The present invention relates to a dynamic test fixture for a motor vehicle, to a test stand and an assembly line, which include the dynamic test fixture, and to preferred applications of the same for testing a stabilizing system of a motor vehicle. The present invention additionally relates to an associated method.
Modern motor vehicles are increasingly equipped with electronic safety systems to improve functional characteristics, in particular the functional safety, of the vehicles. Examples of such safety systems include the so-called antilocking system, which acts on the brakes of a vehicle (“ABS” system), and the anti-skid control (“ASR” system), which influences the drive of a vehicle. Another important system component that is increasingly used in the construction of motor vehicles is a stabilizing system, which is designed to prevent the vehicle from tipping or overturning, in particular when the motor vehicle is driven on extremely curvy roads. Such systems are also called “electronic stability programs” (“ESP” devices). Specifically, these systems cause the braking of a wheel when the motor vehicle goes into a tilted position or into a spin during extreme driving maneuvers.
To assure the quality of such safety devices during the final inspection of a motor vehicle, for example, it is necessary to test the functionality of these devices when they are installed in the motor vehicle. Therein, it is a particular problem that, to date, no suitable devices have been available for testing a stabilizing system in a completely assembled vehicle that is ready to be delivered to the customer. More specifically, such testing relates to the functionality of position and/or acceleration sensors installed in the vehicle, and to their proper connection to an electronic controller.
German laid-open patent application DE 21 65 244 teaches a device for raising and tilting vehicles. The device has a lift assembly that includes a raisable part. During the lifting process, the raisable part acts on the base of the vehicle. Further, the lift assembly allows the raised vehicle to be tilted around its transverse axis.
In addition, European Patent Application EP 0 378 743 A1 teaches a device for raising vehicles. The device has guide rails, via which the vehicle can be positioned above the lifting device. During the lifting process, the device acts on the base of the vehicle, while the guide rails are lowered. The lift assembly allows the raised vehicle to be tilted around its transverse and longitudinal axes.
Published International Patent Application WO 96/26152 teaches a device for repairing vehicle chassis, whereby the vehicle is positioned above a support frame by means of a ramp. During the lifting process, the support frame acts on the vehicle base and allows the raised vehicle to be tilted around its transverse and longitudinal axes.
German laid-open patent application DE 31 44 621 A1 too teaches a lifting device for a motor vehicle. The lifting device is designed as a conveyor carriage: that acts on the vehicle base during the lifting process.
The prior art lifting devices are of a stationary type; that is, they raise a vehicle into a position for performing maintenance and repair operations. Generally, in order to perform these operations, the vehicle must be held still for a considerable period of time in this raised and, if necessary, inclined position. Any movements of the vehicle would interfere with the performance of these operations.